BS 5351: Steel ball valves for the petroleum, petrochemical and allied industries

BS 5351 Standard specifies the valve seat and body pressure/temperature ratings, and the design, including materials, dimensions, operation, performance, testing and marking, of straightway steel ball valves having specified wall thickness, an antistatic feature and fire tested design.

BS 5351 specifies full bore and reduced bore valves of one piece or split body construction with balls which may be seat supported or trunnion supported.

The ranges of valves covered by this standard are given in Table 1 and Table 2 (see also clauses 4 and 5).

BS 5351 standard does not cover the installation of ball valves.

NOTE 1 The titles of publications referred to in this standard are listed on page 22 and the inside back cover.

NOTE 2 The information to be supplied by the purchaser at the time of his enquiry/order is given in the form of a data sheet in Appendix A.

11 Pressure Testing

All valves shall be pressure tested in accordancewith BS6755-1 and for the minimum test durationsgiven in Table 14, and additionally:

a) the shell test shall be a hydrostatic test andthere shall be no visually detectable leakage fromthe valve including the valve stem seals;

b) the seat test shall be either pneumatic orhydrostatic.

NOTE 1 If a particular type of seat test is required, i.e.pneumatic or hydrostatic, the purchaser should state therequirement in the enquiry and/or order (see Appendix A).

NOTE 2 The hydrostatic seat test is an optional test for softseated ball valves. The purchaser should state anyrequirement for hydrostatic pressure tests on soft seated ballvalves in the enquiry and/or order (see Appendix A).

NOTE 3 It should be noted that soft seated valves, when hydrostatically tested, might have a reduced performancecapability in some subsequent services at low differentialpressures. In these cases the manufacturer should beconsulted.

c) the seatbe leakage rate A, i.e.no visually detectableleakage. If a production pressure test certificate is issuedit shall contain a statement by the manufacturerconfirming that the valves have been tested inaccordance with this standard, and stating theactual pressures and medium used in the tests.

NOTE If a test certificate is required this should be specified bythe purchaser on the enquiry and/or order for the valves(see Appendix A).